Clamp-on bucket attachment for loader bucket

ABSTRACT

A clamp-on bucket attachment having hinged fork arms, which prevent the fork arms from being bent or damaged when the loader bucket is lowered while tilted downward. The clamp-on bucket attachment of this invention includes a pivoting fork arm and a separate clamping member detachably mounted to the loader bucket. The fork arm is pivotally connected to the clamp member for free movement between a tilt position where the fork arm is angled with respect to the bottom of the loader bucket and a lift position where the fork arm is parallel to the bottom of the loader bucket. In the lift position, the fork arm abuts against the clamp member to hold it parallel to the bottom of the loader bucket under load.

This invention relates to clamp-on bucket fork attachments for front end loaders and skid loaders, and particularly, clamp-on pallet and debris fork attachment.

BACKGROUND AND SUMMARY OF THE INVENTION

Clamp-on bucket attachments, such as pallet forks and debris forks are popular accessories for front-end loaders, skid steer loaders, and loader tractors. Pallet forks consist of elongated fork arms detachably mounted to the bucket of front-end loaders by a clamping mechanism. Similarly, debris forks consists of a number of rake arms clamped to the loader bucket. Heretofore, bucket fork attachments, particularly pallet forks and debris forks, have frequently bent or damaged when the loader bucket is lowered while tilted downward, which drives the end of the forks into the ground under the full weight of the loader.

The present invention seeks to provide a clamp-on bucket attachment having hinged fork arms, which prevent the fork arms from being bent or damaged when the loader bucket is lowered while tilted downward. The clamp-on bucket attachment of this invention includes a pivoting fork arm and a separate clamping member detachably mounted to the loader bucket. The fork arms are pivotally connected to the clamp members for free movement between a tilted position where the fork arm is angled with respect to the bottom of the loader bucket and a lift position where the fork arm is parallel to the bottom of the loader bucket. In the lift position, the fork arm abuts against a clamp member to hold it parallel to the bottom of the loader bucket under load.

The above described features and advantages, as well as others, will become more readily apparent to those of ordinary skill in the art by reference to the following detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention may take form in various system and method components and arrangement of system and method components. The drawings are only for purposes of illustrating exemplary embodiments and are not to be construed as limiting the invention. The drawings illustrate the present invention, in which:

FIG. 1 is a perspective view of an embodiment of a bucket fork of this invention;

FIG. 2 is a perspective view of a pair of bucket forks of FIG. 1 mounted to a conventional loader bucket;

FIG. 3 is a side view of the bucket fork of FIG. 1 mounted to a conventional loader bucket with the fork shown pivoted upward in the tilt position;

FIG. 4 is a side view of the bucket fork of FIG. 1 in the lift position;

FIG. 5 is a partial side view of a prior art bucket fork mounted to a loader bucket failing when the bucket is tilted and lowered;

FIG. 6 is a partial side view of the bucket fork of FIG. 1 mounted to a loader bucket pivoting when the bucket is tilted and lowered; and

FIGS. 7-9 are side views of a conventional loader using the bucket forks of FIG. 1 to lift and move a pallet of goods.

DESCRIPTION OF THE PREFERRED EMBODIMENT

In the following detailed description of the preferred embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is understood that other embodiments may be utilized and that logical, structural, mechanical, electrical, and chemical changes may be made without departing from the spirit or scope of the invention. To avoid detail not necessary to enable those skilled in the art to practice the invention, the description may omit certain information known to those skilled in the art. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims.

Referring now to the drawings, FIGS. 1-9 illustrate an exemplary pallet fork attachment 100 embodying the teaching of this invention. While the teachings of this invention are illustrated as a pallet fork attachment, one skilled in the art may readily apply those teaching in various alternative embodiments of clamp-on bucket attachments, such as debris forks without deviating from the spirit of the invention. In addition, pallet fork attachment 100 is shown in the figures for simplicity of illustration and explanation used on a conventional skid steer loader 10, although the fork attachment may be mounted to the bucket of any front end loaders, skid steer loaders, loader tractors and similar material and earth moving equipment having a lift bucket.

Pallet fork attachment 100 includes a pivoting fork arm 110 and a clamping member 120. Fork arm 110 is constructed from a length of rectangular metal tube, such as steel or aluminum. A pair of side hinge plates 112 are mounted on the proximal end of fork arm 110, which act as a clevis for the hinge mechanism of attachment 100. The distal end of fork arm 110 terminates in an angle end plate 114.

Clamp member 120 is constructed of a metal, such as steel or aluminum from various welded sections of rectangular tubing, blocks and plates. Clamp member 120 includes a lower clamp arm 122 and an upper clamp arm 124 connected by a pair of buttress plates 126. As shown, upper clamp arm 24 is spaced parallel over lower clamp arm 22, which provides a space 121 for receiving the front edge of the loader bucket 4 (FIGS. 2 and 3). Clamp member 120 is held to loader bucket 12 by a threaded screw clamp 130 that is turned into a thread bore in upper clamp arm 124. Screw clamp 130 includes a hex head 132 or handle (not shown), and a swiveling clamp head 134. A short cylindrical dowel or lock bar 136 is welded laterally to the bottom of upper clamp arm 124 adjacent buttress plates 126. As shown, lock bar 136 is spaced over the lower clamp arm 122 to create a narrow space for restrictively receiving the front or “cutting edge” of the loader bucket 12. When clamp member 120 is mounted to load bucket 12, the cutting edge of loader bucket 12 inserts under lock bar 136 and abuts buttress plates 126 and a reinforcing stop block (not shown) and is held securely by clamp screw 130. A pair of leveling blocks or pads 136 are welded to the top of the distal end of lower clamp member 122, which accommodate for the cutting edge plate 14 mounted under the cutting edge of conventional loader buckets. Leveling pads 138 ensure that clamp member 120 seats squarely on loader bucket 12 with the cutting edge of the loader bucket inserted under lock bar 136.

Clamp member 120 also includes a hinge block 140. Fork arm 110 is pivotally connected to clamp member 120 by a bolt or pivot pin 142 that extends to aligned lateral bores in hinge block 140 and side hinge plates 112. Fork arm 110 pivots about the axis of pin 142, which is generally parallel to the bottom of loader bucket 12 and perpendicular to the longitudinal axis of fork part 110 and upper and lower clamp arms 122 and 124 of clamp member 120. As shown, fork arm 110 pivots between a tilt position (FIG. 3) where the fork arm is angled with respect to the bottom of the loader bucket 12 and a lift position (FIG. 4) where the fork arm is parallel to the bottom of the loader bucket 12. One skilled in the art will note that the hinge mechanism of this invention prevents inadvertent damage to the clamp-on bucket attachment. The pivoting action of the fork arms allows the load bucket to be lowered without particular regard to the tilt angle of the bucket. When loader bucket 12 is lowered while tilted downward, which would drive conventional pallet forks or debris forks into the ground potentially bending or breaking the forks (FIG. 5), the hinged fork arms of this invention pivot upward as they contact the ground (FIG. 6). The hinged fork arms can slide across the ground until the tilt of the loader bucket levels and the fork arms pivot into the lift position. In the lift position (FIG. 4), the end of fork arm 110 abuts against clamp member 120 to hold the fork arm parallel to the bottom of the loader bucket under load, so that the fork arms can be used to lift pallets and the like.

It should be apparent from the foregoing that an invention having significant advantages has been provided. While the invention is shown in only a few of its forms, it is not just limited but is susceptible to various changes and modifications without departing from the spirit thereof.

The embodiment of the present invention herein described and illustrated is not intended to be exhaustive or to limit the invention to the precise form disclosed. It is presented to explain the invention so that others skilled in the art might utilize its teachings. The embodiment of the present invention may be modified within the scope of the following claims. 

I claim:
 1. A fork attachment for a loader bucket having a flat bottom thereof, the attachment comprising: a clamp member adapted for detachably mounting to the loader bucket; and an elongated fork part pivotally connected to the clamp member for movement between a first position where the fork part is parallel to the bucket bottom and a second position where the fork part is angled to the bucket bottom.
 2. The attachment of claim 1 wherein the fork part being pivotally connected to the clamp member for movement about an axis parallel to the bucket bottom and perpendicular to the longitudinal axis of the fork park between the first position and the second position.
 3. The attachment of claim 3 wherein the clamping member includes a stop and a hinge block, the fork part pivotally connected to the hinge block and abutting the stop when the fork part is in the first position.
 4. The attachment of claim 1 wherein the fork part includes a clevis hinged to the hinge block, the fork part also includes a flat contact face that abuts the stop.
 5. The attachment of claim * wherein the fork part terminates at its distal end in an angled face.
 6. The attachment of claim 1 wherein the clamp member includes a first clamp arm, a second clamp arm spaced parallel to the first clamp arm for receiving the bottom of the loader bucket therebetween, a screw part turned into a threaded lateral bore in the second clamp arm for operatively engaging the bottom of the loader bucket to secure the clamp member to the loader bucket.
 7. The attachment of claim 6 wherein the clamp member also includes an offset part mounted to the second clamp between the second clamp arm and spaced over the first clamp arm. 